Spearmint Energy secures US$250 million for two Texas BESS totalling 400MWh

April 17, 2025
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Battery storage developer and operator Spearmint Energy has secured US$250 million for two battery energy storage system (BESS) projects located in Texas, US, totalling 400MWh.

The Tierra Seca BESS located in Del Rio, Texas and the Seven Flags BESS located in Laredo, Texas both have a an output of 100MW to 200MWh energy storage capacity.

The US$250 million financing comprises US$59 million in construction-to-term loan facilities provided by Manulife, US$95 million in tax equity bridge Loan facilities provided by East West Bank and Investec and US$98 million in tax equity commitments from Sugar Creek Capital.

The projects are both under construction from engineering, procurement and construction (EPC) contractor MA Mortenson Company.

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Tierra Seca and Seven Flags will both utilise inverter and energy storage system supplier Sungrow’s PowerTitan 2.0 energy storage platform comprised of lithium iron phosphate (LFP) cells.

In 2022, Energy-Storage.news reported that Black Mountain Energy Storage (BMES) had signed an exclusivity agreement with Cypress Creek Renewables for the Tierra Seca and Seven Flags BESS, as well as two others.

ESN asked Spearmint Energy for clarification as to whether these were in fact the same projects but did not hear back by the time of publication.

Spearmint recently became active in the Electric Reliability Council of Texas (ERCOT) market when in January of last year, the company brought online its first major project in the region.

The 150MW/300MWh Revolution BESS was acquired in June 2022, EPC services for this project were also provided by Mortensen and used 134 BESS containers from Sungrow.

Spearmint claims to currently have more than 20 projects totalling over 13GWh of capacity.

The company saw a setback in November 2024 in the Midcontinent Independent System Operator (MISO) market, after the City of Kokomo Plan Commission in Indiana rejected a rezoning request for the company’s 400MW Pumpkinvine BESS.

Spearmint has not provided additional information about the Pumpkinvine BESS but it has made clear that it is continuing to target the MISO and ERCOT markets.

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